1. Field of the Invention
The invention relates to an alkaline dry cell, and more particularly to an alkaline dry cell having characteristics particularly suitable as power for the flash of a camera.
2. Description of the Related Art
The alkaline dry cell is generally formed of a hollow cylindrically-formed cathode depolarizing mixture having electrolytic manganese dioxide as an active material and a gel anode having zinc alloy powder as an active material, which are placed with a cylindrical separator therebetween in a metallic cathode can which is a closed-end cylinder and doubles as a cathode terminal, and a metallic anode current collector which is inserted into the gel anode.
Recently, demands for the alkaline dry cell is sharply expanding with the increased use of various equipment and, researches are being made vigorously to increase its capacity. To increase the capacity, there is a method which, for example, increases the inner volume of the cell by making the cathode can and the separator thinner, so that an amount of the active material can be increased.
The alkaline dry cell has long been used as power for a remote control and a personal portable. In addition, a large demand is expected for the alkaline dry cell as power for a personal handy phone and the flash of a single-use camera in these years. To use the alkaline dry cell as power for the flash of a single-use camera, it is necessary to get a large current temporarily but an amount of the active material is not required to be increased largely. For example, cells now available on the market have a utilization factor of less than 30% of the active material. Thus, its utilization factor is small. Therefore, the improvement being made in the alkaline dry cell in these years, namely a method of increasing the inner capacity of the cell in order to increase the theoretical capacity, is not necessarily suitable to use it as power for the flash of a single-use camera.
In view of the aforementioned circumstances, the invention was achieved to provide an alkaline dry cell having performance particularly suitable as power for the flash of a single-use camera.